The overall objective of this study is to explore an innovative treatment with metformin, an oral hypoglycemiant, and to assess the fitness level of children with non-insulin dependent diabetes mellitus (NIDDM-Type 2 diabetes). NIDDM is a well recognized entity in adults, but far less is known about NIDDM in children. Recent data show that the incidence of NIDDM in children is increasing, particularly in genetically predisposed ethnic groups (i.e. African-Americans, Hispanics and Native Americans). This phenomenon is likely the result of the rising incidence of obesity observed in American children. The consequences of hyperinsulinemia and obesity result in profound morbidity for the child and will likely cause long-term impairment of health in adulthood. In adults, hyperinsulinemia is associated with hypertension, hyperlipidemia and cardiovascular disease. As the incidence of complications of diabetes increase with the duration of illness and inadequate control, it is likely that children with NIDDM will develop complications at a younger age than adults. Currently, most children with NIDDM are treated with insulin injections. An appropriate alternative to insulin, with which treatment compliance may increase, is essential to prevent the complications of the disease in these children.